Finger type circuit regulator with auxiliary circuit-breaking arrangement



May 3 1955 Filed April 6, 1951 A. M. COHEN FINGER TYPE CIRCUIT REGULATOR WITH AUXILIARY CIRCUIT-BREAKING ARRANGEMENT 3 Sheets-Sheet l ENVENTOR. 4/57/90? M COHEN ATTOE/i/EYS y 3, 1955 A. M. COHEN 2,707,735

FINGER TYPE CIRCUIT REGULATOR WITH AUXILIARY CIRCUIT-BREAKING ARRANGEMENT File P 1951 3 Sheets-Sheet 2 'EI I 1 as. 1 32 lq lA 5 I 80 I l IT 1 t 5 mo 1 70 8 7 f E H 42 26 \L "2 I A 6- 0 5 A 22 {3 /02 IN VEN TOR. 77/02 M. (Of/EN BYW V A-4% May 3, 1955 A. M. COHEN 2,707,735

FINGER TYPE CIRCUIT REGULATOR WITH AUXILIARY CIRCUIT-BREAKING ARRANGEMENT Filed April 6 1951 3 Sheets-Sheet 3 l 4 p J I L la 6 1040 8 I J /24 80 I 66 INVENTOR. O 62 4277/02 M. cw/H/ F4 2 BY 22 w m d L i 20 7 /00 q Arrow/5x5 United States Patent 0' FINGER TYPE CIRCUIT REGULATOR WITH AUXILIARY CIRCUIT-BREAKING ARRANGE- MENT Arthur M. Cohen, Westport, Conn.

Application April 6, 1951, Serial No. 219,659

18 Claims. (Cl. 200-104) The present invention relates to an improvement in finger type circuit regulators and particular advantages of the instant construction are specifically pertinent to regu lators of the type disclosed in my copending applications Ser. No. 34,517, filed June 22, 1948, entitled Finger Type Circuit Regulator, Ser. No. 49,726, filed September 17, 1948, now Patent No. 2,650,957, September 1, 1953, entitled Finger Type Circuit Regulator, Contact Assembly Therefor, and Method of Making Same, and Ser. No. 157,948, filed April 25, 1950, now Patent No. 2,550,779, May 1, 1951, entitled Electromagnetic Unit.

Sensitive finger-type regulators are characterized by having a plurality of comparatively flimsy movable contacts, each associated with an individual fixed contact so as to define a contact pair, the movable contacts being weakly resiliently urged into engagement with their respec- 2" tive fixed contacts and being sequentially engageable by a finger-lifting member operatively connected to a electromagnetically actuated armature. Each of the contact pairs is adapted to be electrically connected to regulatory circuit components such as resistors in a network such that, in one embodiment, as more and more of the contact pairs are sequentially opened, a greater and greater amount of resistance is inserted into the circuit being controlled, so as to compensate, for example, for a rise in the voltage of that circuit.

One of the primary engineering requirements of a regulater of that type is that the time of response of such a regulator should be very low, thus not only rendering the regulator sensitive to smal or rapid fluctuations occurring in the circuit being controlled, but also, and in some instances more importantly, permitting it to achieve regulation not in a stepwise manner, dependent upon the discrete magnitudes of the individual circuit regulating elements involved, but instead in a substantially smooth and stepless manner, this being accomplished because of the tendency of the armature to vibrate rapidly between a position where a given number of contact pairs are open and a position in which an additional contact pair is open, the vibration giving rise to an averaging or integrating effect of the two discrete steps of the regulator between i which the armature is vibrated.

To achieve this most important result, the characteristics of the regulator must satisfy certain criteria. The resilient forces acting on the armature and contact-lifting member when in operative circuit-regulating position must he very carefully balanced and should have as low a magnitude as is feasible, since strong resilient forces exerted on the moving parts of the regulator would tend to increase the moment of inertia of those parts and thus greatly reduce the sensitivity, and hence the operativeness, of the device. Accordingly, the resilient force which urges the movable contacts against their respective fixed contacts is made minimal as through the use of comparatively flimsy and thin spring fingers for the movable contacts themselves. When the finger-lifting member engages these fingers in sequence and lifts them from their respective fixed contacts the fingers are resiliently distorted, and

2,707,735 Patented May 3, 1955 that resiliency necessarily asserts a force against the member which moves them. This force must necessarily be as light as possible in order to avoid the inertia reaction just described.

it has further been found most desirable to so construct the contact assembly and the contact-lifting member that a clean break is made between fixed and movable contacts as the movable contact is lifted from the fixed contact. Any other type of circuit breaking would introduce mechanical hysteresis and coulomb friction into the device, thus in effect putting a time constant into the mechanical operation of the moving parts, a most undesirable result. Therefore the movable contacts are lifted from the fixed contacts in as substantially rectilinear motion as is possible. This, however, being the antithesis of a wiping action between contacts, has the disadvantage that the conductivity between the contacts when they are engaged is not as great as might be desired. With successive makes and breaks of a circuit, non-conductive films tend to form between the contacts. A wiping or sliding engagement and disengagement of the contacts tend to destroy such films, but in the absence of a wiping action, and instead in the presence of a substantially rectilinear movement of the movable contacts, these films form and remain unbroken and thus impair the ability of the contacts to pass current when low voltages are involved. This drawback might be overcome through the use of high contact pressure, said pressure tending to break down the film even without a wiping action, but the use of high contact pressure would necessarily add to the resilient forces active on the armature during regulation and hence would destroy or impair the sensitivity of response of the regulater and its characteristic of smooth regulation in an infinite number of steps.

This inherent limitation in the regulator structure is not particularly significant when comparatively high voltages, on the order of 110 volts, are involved. However, many pieces of equipment, and particularly much electrical equipment used in vehicles such as aircraft and automobiles, are designed to operate on considerably lower voltages, for example, 6 volts, and on comparatively high amperage such as 5 amperes. Since an appreciable voltage drop across a contact pair occurs when the contact pressure is low and no Wiping action takes place, it becomes necessary, in regulating low voltage and high amperage equipment, for each step of regulation controlled by a given contact pair to involve an appreciable voltage change. However, with but little voltage initially available, the number of steps which can be provided must therefore necessarily be comparatively limited. This is undesirable. If the individual steps are too great, and if not enough steps are provided over the desired regulatory range, the mechanical characteristics of the moving parts of the regulator will not permit proper oscillation between the steps, and consequently eifective regulation will be discontinuous rather than in a smoothly continuous curve.

Another problem arising from the regulation of low voltage and high amperage equipment is that, with a small amount of voltage available, it is undesirable to have any additional resistance at all in the circuit when the regulator is not needed. This is not so much because of the energy loss in that resistor as it is because the presence of the resistance necessarily involves a voltage drop, and hence a dissipation of scarce voltage. This disadvantage might be cured by connecting the first contact pair to be opened directly between line and load so that it will function as a short circuit. Hence when the regulator is not effectively energized no resistance will be placed in the circuit. However, this expedient is not feasible, because each time that the short circuiting contact pair is opened the entire line current must be broken, and the 3. flimsiness of the movable contact required for proper sensitivity and smoothness of regulation militates against the control, by a single contact pair, of such a large amount of current as amperes over an extended period of time. The normal manner of regulation for equipment of this type is to connect the regulating resistors in parallel so that the line current will divide through them and thus, when a. given contact pair in series with oneof the resistors is opened, only a fraction of the total line current is broken thereby. The use of a short circuitingcontact pair controlled by the armature during its regulating motion and remaining inoperative connection with: it during regulation is not permissible because the contact would have to be so massive, in order to break the full line current, as to have an undesirable-mechanical effect on the moving parts.

Itwillbe obvious thatthe considerations outlined above point away from the use of a set of. massive contacts if sensitivity and smoothness of response are to be maintained. However, massive contacts are indicated when equipment operating on low voltage and high current is to be regulated. I have discovered that these contradictor-y considerations, which have in the past been deemed'so incompatible as to completely rule out use of sensitive finger-type regulators in applications of this nature, can be reconciled by so positioning the massive contacts that they do not interfere with the mechanical action of the moving parts of the regulator when they actuate the comparatively flimsy contact pairs to provide the desired sensitivity and smoothness of operation.

More specifically, I position the comparatively massive contacts on the regulator so that they are acted upon by the armature to close the circuit through them while the armature isin a position of rest or, in other words, before the armature has reached the range of movement within which the comparatively flimsy contact pairs are engaged and actuated. In this way, massive contacts can be employed which are capable of carrying and breaking the full line current. They can therefore be connected as a short circuit around the comparatively flimsy contact pairs and the circuit regulating components to which the latter are connected. The first step in the regulation achieved by a regulator thus constructed: will therefore boot a comparatively coarse nature when compared with the individual steps of regulation'controlledby the flimsy contacts, and will in effect permit theregulator to offer no-resistance during normal operation of= the circuit in which it is connected, but at the same time will permit the regulator to have its wonted sensitivity and smoothness of'response when-accurate regulation'is necessary.

The physical modification of the standard regulator as described in the aforementioned copending applications in order to be capable of regulatingequipment operating on a low voltage but with a high current is very readily accomplished while still retaining the desirable characteristics of design claimed in said applications, from which design the exceptional operating characteristics of the regulator derive. The basic, portions of the regulator of the present invention may be identical with those of the regulator described in the aforementioned applications, the only change in structure being the addition of the comparatively massive contacts-in a position such that they. achieve the above stated objectives and do not interfere with the'proper functioning of'the regulator. indeed, certain mechanical advantages are achieved in the construction involved in the present invention, these advantages revolving about the more balanced character of the armature and the cushioned seating of that armature against its positive stop when it is ina position of rest.

To the accomplishment of. the above, and to such otherobjects as may hereinafter appear, the present invention relates to the structure of anelectric regulator as defined in the appended claims and. as described. in this specificaiii 4;. tion taken together with the accompanying drawings in which:

Fig. 1 is a three-quarter perspective exploded view, taken partially from the front, showing the regulator;

Fig. 1A is a side elevational view thereof, partially in cross section;

Fig. 2 is a view similar to Fig; 1, but taken partially from the rear and with the electromagnet, dashpot and top mounting plate omitted, and showing the location of the comparatively massive contacts;

Fig. 3 is a top plan view of that portion of the massive contact which is mounted on the frame of the regulator;

Fig. 4 is a schematic circuit diagram showingone way in which the regulator of the instant invention can be employed;

Fig. 5 is a similar view showing a modified mode of employment thereof;

Fig. 6 is a schematic side elevational view showing the position of the armature, contact-lifting member, and circuit controlling assemblies when the armature is in its position of rest;

Fig. 7 is an end elevational view of the sub-assembly of Fig. 6 taken from the right-hand side thereof;

Fig; 8 is a view of the sub-assembly of Fig. 6 showing:

the position which the parts assume with respect to the circuit controlling assemblies before any of the comparatively flimsy contacts have been engaged and after the comparatively massive contacts have been opened;

Fig. 9 is an end elevational view of the sub-assembly of Fig. 8 showing an arrangement of the comparatively massive contacts particularly adapted for use in the circuit of Fig. 5; and

Fig. 10 is a view of the sub-assembly of Fig. 6 showing the position of the parts after at least one of the relatively flimsy contacts has been engaged.

The regulator of the present invention ashere specifically illustrated for the most part conforms to the details of that disclosed in the said copending applications; It comprises an insulating plate 2, formed of any suitable insulating material, from which connection prongs 4 depend, so that the entire unit is adapted to be plugged into a suitable socket. A first circuit controlling assembly generally designated X comprises a plaque 14 at one end of which aplurality of fixed contacts 16 are secured, these contacts being connected to an appropriateone of the prongs 4. Also secured to the plaque 14 are a plurality of relatively flimsy resilient fingers 29, one for each fixed contact 16. The fingers 20 in the form here disclosed are formed of thin strips of a resilient material which is a good conductor of electricity. The free ends 22 of the fingers 20 project out beyond. the plaque 14 and the fingers 20 are normally urged by their inherent resiliency into electrical connection with the fixed contacts 1.6, thus defining movable contacts. An insulating clamp 24 serves to secure the inner ends of the fingers 29 to the plaque 14. A pair of mounting arms 26 are secured tothe plaque 14 and are spaced from the plate 2 by means of sleeves 28, the sleeves being appropriately positioned by passing over screws 30 extending upwardly g from the insulating plate 2.

The electromagnet generally designated 32. which defines the armature moving mechanism comprises an energizing coil 34 wound around a magnetizable core 36, the upper end of the core being secured within the magnetizable top plate 38 of electromagnet 32. Magnetizable. spacers 40 are also secured at one end to the magnetic top plate 38and at their other end have screw threaded projections 42'which pass through apertures 43 in the magnetizable bottom plate 44. The core 36 extends downwardly through an aperture 46 in the bottom plate 4-4. Leads 48, which passthrough apertures49 in the bottom plate 44, connect the coil 34 to appropriate prongs 4.

Internally'threaded' spacers 50 and 52 are positioned below the magnet bottom plate 44 so as to receive'vthe. threadedprojecting; portions 42 of. the magneti'zable;

spacers 40, thus maintaining the electromagnet 32 in assembled position, the spacers 52 being positioned between the first circuit controlling assembly X and the magnet bottom plate 44 so as to be threadedly engageable with the screws 30.

The armature 56 is in the form of a fiat sheet of magnetizable material to the upper surface of which is secured a flexible sheet defining the magnet mounting member 58, the mounting member 58 being in turn secured to the magnet bottom plate 44 between said plate 44 and the spacers 52. The armature mounting member 58 is so constructed that the armature 56 is pivotable about an axis parallel to the plane of the lower surface of the magnet bottom plate 44 and parallel to a line between the axes of the spacers 52. The right hand portion of the armature 56, as viewed in Fig. l, is provided with an aperture 60 concentrically arrangeable with the downwardly projecting portion of the core 36 so that said projecting portion is receivable therein. The left hand portion of the armature 56 extends out beyond the electromagnet 32, and it is to that left hand portion of the armature 56 that the armature mounting member 58 is fastened as by means of rivets. The spacers 59 are pro vided with flanges 64 which are adapted to engage with the extreme right hand portions of the armature 56 so contact with the fingers 20 and thus move them one after the other out of electrical connection with the fixed contacts 16 with a substantially rectilinear movement, no wiping or sliding taking place between fixed and movable contacts 16 and 22 or between the contact lifting member 66 and the movable contacts 22.

The extreme left hand portion 70 of the armature I mounting member 58 extends out beyond the armature 56 and is receivable in the aperture 72 in the contact lifting member 66 so as to be passable between the upper surface of said aperture 72 and the lug 74 formed therein.

The portion 71) of the armature mounting member 58 is provided with an aperture 76 through which the lug 74 is receivable, and by means of this lug and aperture connection the contact lifting member 66 is operatively connected to the armature 56 on one side of the pivotal axis of the latter so as to be moved thereby and so as to be pivotable with respect thereto as the armature 56 is pivoted on the magnet bottom plate 44.

In order to ensure that the contact lifting member 66 maintains its proper position, so that the entire width of its inclined lower edge 68 will make contact with the ends 22 of the fingers 20, a pair of springs 80 are active thereon, one end of each of the springs being securable inapertures 82 in the member 66 and the other end of the springs being securable in notches 84 in the frame portions 86 which may be integral extensions of the magnet top plate 38. The frame portions 86 are preferably made relatively narrow so that they may, if desired, be manually bendable so as to vary the tension which the springs 80 exert upon the contact lifting member 66,

The dashpot generally designated 88 comprises a cylinder in which a piston is slidable. The dashpot 88 is secured to the unit by means of screws 94 which pass through other frame portions 96, also preferably integral extensions of the magnet top plate 38, these frame portions 96 being separated so as to provide access to the adjusting screw 98 which controls the air escape from thedashpot 88 and hence determines the extent of its damping action. The plunger of the dashpot 88 is secured to the finger lifting member 66 by engagement 6 of the angular connection 100, here shown as of L-shape', in the aperture 101 of the member 66, in which it may be secured by solder.

Spacers 102 are mounted toward the rear of the plate 2, screws 104 being passable therethrough and into the spacers 50 so as to complete assembly of the regulating unit on the mounting plate 2.

The second or auxiliary circuit controlling assembly, generally designated Y which is defined by a circuit breaking assembly of comparatively massive construction so as to be capable of breaking currents greater than those which can be broken by the comparatively flimsy contact pairs 16, 22 of the first circuit controlling assembly X, is defined by a first portion which is substantially stationary and which is mounted on the frame of the regulator, and a second portion in the form of an actuating component which is operatively connected to the armature 56 and is movable therewith.

The said first portion of the second circuit controlling assembly Y is mounted on the frame of the regulator between the spacers 50 and 102. In the form here specifically disclosed, and best shown in Fig. 3, it comprises a U-shaped support 196 formed of an insulating material and having bosses 108 with apertures 110 through which the screws 164 can pass, these bosses being positioned atop the spacers 102. Mounted on the support 1116 are a pair of U-shaped conductive strips 112 fastened to the support 106 by eyelets 114 and having bosses 116 with apertures 118 concentric with the apertures but of a greater diameter than the apertures 110 so that the screws 104 do not make contact therewith. Insulating washers 120 are preferably positioned between the bosses 116 and the spacers 50, so that the conductive strips 112 are insulated from other parts of the regulator and, since they are separated from one another, they define separate and unconnected conductive elements. Leads 122 may be electrically connected to the individual strips 112 in any suitable manner, as by being passed through the outer eyelets 114 and soldered in position.

The strips 112 include arms 124 which extend toward one another but which do not engage one another. Since the support 196 does not extend under the arms 124, those arms are mounted in cantilever fashion and, because they are formed of a comparatively thin strip of resilient material, thicker, however, than the fingers 21) which define the movable contacts of the first circuit controlling assembly X, they can bend about axes substantially parallel to the inner edges 126 of the support 1536 when pressure is exerted thereupon. It will be noted that the bending axes of the arms 124 are perpendicular to the pivotal axis of the armature 56. It is preferred that the inner portions of the arms 124 have upstruck contact portions 128 to facilitate circuit control.

The second portion or actuating component of the second circuit controlling assembly Y is defined by a conductive bridging element in the form of a cup 130 mounted on the inner end of the armature 56 by means of rivet 132. The dimensions of this bridging element 130 are such that, when the armature is pivoted in a clockwise direction by the action of the springs 80, the element 130 will engage with and make electrical connection with the arms 124 of the strips 112, preferably with the upstruck contact portions 128 thereof, and before the armature 56 has reached its postiive stop in this direction of pivotable motion as defined by the flanges 64 on the spacers 50. In this position, hereinafter termed the first position of the contact-actuating member (that term including either or both of the armature 56 and the contact-lifting member 66), engagement of the first and second portions of the second circuit controlling assembly Y closes the circuit therethrough. In that position, none of the contact pairs 16, 22 of the first circuit controlling assembly are engaged by the contact-lifting member 66.

At this point it may be noted that, since the bridging element 130 engages both of the arms 124 before the positive stop of the armature 56 is reached, they force of the springs 80 in urging the armature 56, to its positive stop will cause the arms 124 to be bent downwardly. This motion has two results. In the first place, the inherent resiliency of the. arms 124. acts to cushion the return of the armature 56 to its positive stop and thus make for better mechanical operation of the regulator. In the second place, since the directions of motion of the bridging element 130 and the contact portions 123 of the arms 124 engaged thereby are somewhat different, due to the fact that the axes about which the arms 124 bend are. displaced from, and indeed are. perpendicular to, the pivotal. axis of the armature 56 to which the bridging element 130 is secured, a wiping action occurs each time the circuit through the second circuit controlling assen1- blyv is made or broken, thus insuring proper functioning of that assembly.

It may be noted that the addition of the bridging element 134] to the armature 56, far from dislocating its mechanical action, has the very advantageous effect of balancing the armature S6 with respect to the contact-lifting member 66 connected thereto on the opposite side of its pivotal axis.

When the electroinagnet 34 is energized so as to pivot the armature 56 in a counter-clockwise direction as viewed in Fig. l, the armature 56 will first move from the. position shown in Fig. 6, which position corresponds to its first position, to an intermediate position shown in Fig. 8, in which the bridging element 13:? willv be disengaged from the arms 124, thus breaking the circuit through the second circuit controlling assembly Y, before the inclined lower edge 68 of the contact-lifting member 66 engages any of the free ends 22- of the fingers 20 which define the movable and comparatively flimsy contacts of the first circuit controlling assembly X.

Thereafter, if the electromagnet 3% is appropriately energized, the armature 56 will continue its counter-clockwise pivoting, will move to the position shown in Fig. 10, which position will be hereinafter termed its second position, one or more of the movable contacts 22 of the first circuit controlling assembly X will be engaged and sequentially lifted from their respective fixed contacts 16, and accurate and smooth regulation will result.

It is important to note that, when the armature is in its intermediate position as shown in Fig. 8 or in its second position. as shown in Fig. 10, the arms 124 are completely disengaged therefrom. Consequently, no matter how massive those arms may be, no matter how strong their inherent resiliency due to their comparatively massive construction, and no matter how much wiping or sliding engagement with fixed contacts 16 and control the circuit through resistors a-j connected in parallel with one another and in parallel with an additional resistor k. This regulator network is connected between a line source of voltage 58 and a load 60, the electromagnet 34 of the regulator being connected across the load. This defines the circuit in which the first circuit controlling assembly X functions. When all of the contact pairs are closed all of the resistors ak are connected in parallel and consequently a small effective resistance is presented between the line 58 and the load 60. If the individual contact pairs A-J are sequentially opened a greater and greater resistance is inserted in the line as controlled by the voltage therein as detected by the electromagnet 34. Even when'the contact pair opens it be apparent that only a fraction of the total current will be brokenthere- 8. by, and when the last contact pair I opens, all of the. current in the circuit will still not be broken, and in addi tion that current will be somewhat decreased from. the value it would otherwise have had because of the magni tude of the regulatory resistance which the openingpf the preceding contact pairs has inserted in the circuit.

The second or massive contact assembly Y is shown schematically in Fig. 4. When the elements 124, 124, 139 are in engagement all the resistors 41 k are bypassed or short-circuited, and consequently the regulator presentsno efiective resistance whatsoever. The wiping action and high contact pressure between the elements of the second circuit controlling assembly Y ensures that the contact resistance between said elements is minimal, so thatv as close to a true shortcircuit as possible is achieved. When the bridging element 130 breaks contact with the arms 12, all of the current in the circuit will be broken, but the construction of the arms 12 4 and bridging element 130 is sufficiently massive so that breaking of such large cur: rents over an extended period of time can be achieved without deterioration.

Fig. 5 represents a modification of the circuit of Fig. 4 in which the movement of the bridging element 13 0 achieves two steps of regulation. When the regulator of the present invention is employed in the system of Fig. 5 the arms 124 are so. initially positioned, either by hav ing a permanent bend formed therein or by utilizing spacers 102 of different heights at different sides of the regulator, that one arm 124, shown as the left hand arm in Fig. 9, will normally assume a more advanced position in the path of motion of the bridging element 130 than the other arm 124), the right hand arm in Fig. 9. This modification further requires that the bridging element 133 be electrically connected in the circuit, as by means of lead 123, directly to one end of the line 58, a resistor I being electrically connected between the arms 124 and 124'. In this system, as the armature 56 starts to move from its first position, contact will first be broken between the bridging element 130 and the arm 124. This will result in a breaking of the short circuit around the first circuit controlling assembly, but will place the resistor Z, which preferably will have a large magnitude, in parallel with the resistors a-k of said first circuit controlling assembly. As the armature 56 continues to move through its intermediate position and to its second position the bridging element 130 will become disengaged from the arm 124, thus removing the resistor I from the circuit. While this is preferably accomplished before any of the contact pairs A-J of the first circuit controlling assembly X are engaged and opened by the contact-lifting member 66, occasions may arise where, because of peculiar circuit designs or regulatory desires, such an effect is not desired. It will be apparent that great flexibility in operation of the regulator of the present invention can be achieved by modifying the normal position of the arm 124, that position being easily adjustable after the regulator has been assembled and while it is being tested merely by manually bending the arm in question.

The problems which have given rise to the. present invention, the structure involved therein, the mode in which that structure solves the problems, the simplicity and inexpensiveness of the construction, and its ready compatability with the basic regulator structure, will all be fully apparent from the above description. With respect to the last feature it may be. here noted that all parts used in the basic regulator, as described in the copending applications may be interchangeably used in the'regulater of the present invention except for the spacers at the rear of the regulator. This constitutes an obvious eco nomic advantage, in that a regulator incapable of controlling low voltage and high amperage, equipment with optimum efficiency can readily be converted to perform such a task in an exceptionally fine manner.

While the present invention has been here described in s conjunction with a. regulator as set forth in the afore mentioned copending applications, and while many of the advantages of the present invention are peculiarly adapted for use with said regulator, the broader aspects of the present invention are not specifically limited to such a regulator, and the constructional details and arrangement of the regulator here disclosed may clearly be varied over wide limits without departing from the spirit of the invention as described in the following claims.

I claim:

1. A circuit regulator comprising a frame, a contactactuating member movably mounted on said frame, resilient means operatively connected to said member so as to urge it to a first position, electromagnetic means active on said member so as, when energized, to move said member to a second position against the action of said resilient means, a first circuit-controlling assembly on said frame including a fixed contact and a contact movable between circuit-making and circuit-breaking positions relative to said fixed contact, said movable contact being resiliently urged to one of said positions, disengaged from said actuating member when said member is in its first position, and operatively engaged by said member as said member moves toward its second position so as to be moved thereby to the other of its positions, and a second circuit-controlling assembly including a first portion mounted on said frame and a second portion operatively connected to said member and moved by said member into operative engagement with said first portion when said member moves to its first position and out of operative engagement with said first portion when said member moves toward its second position, said operative engagement or disengagement of said first and second portions actuating said second circuit-controlling assembly.

2. The circuit regulator of claim 1, in which said first portion of said second circuit-controlling assembly is resiliently mounted on said frame, said second portion moving into engagement with said first portion and moving said first portion against said resilience when said member moves to its first position.

3. The circuit regulator of claim 2, in which said first and second portions form parts of an electrical circuit when engaged, and in which the engaging surfaces of said first and second portions move laterally over one another during engagement and disengagement, so that a Wiping effect results.

4. The circuit regulator of claim 2, in which, as said member moves from its first to its second position, said second portion is disengaged from said first portion of said second circuit-controlling assembly before said movable contact of said first circuit-controlling assembly is engaged by said member, so that the resilience of said first portion is not active on said member while said member is engaged with said movable contact.

5. The circuit regulator of claim 2, in which said first and second portions form parts of an electrical circuit when engaged, and in which the engaging surfaces of said first and second portions laterally over one another during engagement and disengagement, so that a wiping effect results, and in which, as said member moves from its first to its second position, said second portion is disengaged from said first portion of said second circuit-controlling assembly before said movable contact of said first circuit-controlling assembly is engaged by said member, so that the resilience of said first portion is not active on said member while said member is engaged with said movable contact.

6. The circuit regulator of claim 1, in which said first circuit-controlling assembly comprises a plurality of fixed contacts and a plurality of movable contacts weakly resiliently urged against respective fixed contacts so as to define a plurality of contact pairs, each of said contact pairs being comparatively flimsy and thus capable of breaking only limited amounts of currents, said movable contacts and said member being so related that said con tact pairs are sequentially opened as said member moves to its second position, in which said second circuit-controlling assembly comprises comparatively massive circuit-breaking portions capable of breaking greater amounts of current, disengagement of said first and second portions being effective to break the current through said assembly and in which, as said member moves from its first to its second position, said second portion is disengaged from the first portion of said second circuitcontrolling assembly, thus breaking the circuit therethrough, before any of the movable contacts of the first circuit-controlling assembly are engaged by said member.

7. The circuit regulator of claim 6, in which the first portion of said second circuit-controlling assembly is resiliently mounted on said frame, said second portion engaging said first portion and moving it against said resilience when said member moves to its first position.

8. The circuit regulator of claim 6, in which the first portion of said second circuit-controlling assembly is resiliently mounted on said frame, said second portion engaging said first portion and moving it against said resilience when said member moves to its first position, in which said first and second portions form parts of an electrical circuit when engaged, and in which the engaging surfaces of said first and second portions move laterally over one another during engagement and disengagement, so that a wiping efiect results.

9. The circuit regulator of claim 1, in which said second circuit-controlling assembly comprises a pair of conductive strips mounted on said frame, extending adjacent but spaced from one another and defining said first portion, and in which a conductive element is operatively connected to said member, simultaneously engageable with both said strips so as to bridge them when said member is in its first position and defines said second portion.

10. The circuit regulator of claim 9, in which said strips are resilient and move at least partially in different directions from said second portion when engaged and moved thereby, so that a wiping action results.

11. The circuit regulator of claim 9, in which said strips are resilient and move at least partially in different direections from said second portion when engaged and moved thereby, so that a wiping action results, and in which said strips normally freely assume different positions along the direction of travel of said second portion, so that contact is broken between one of said strips and said second portion before contact is broken between the other of said strips and said second portion as said member moves from its first toward its second position.

12. The circuit regulator of claim 1, in which, as said member moves from its first to its second position, said second portion is disengaged from said first portion of said second circuit-controlling assembly before said movable contact of said first circuit-controlling assembly is engaged by said member.

13. The circuit regulator of claim 18, in which said arms are resilient and are mounted in cantilever fashion on said frame so as to bend about axes displaced from the pivotal axis of said armature when engaged by said actuating component, said armature having a degree of movement from the point where said actuating component first engages said arm to the first position of said armature, thereby achieving relative motion between said actuating component and said arms while they are engaged so as to define a wiping contact engagement.

14. The circuit regulator of claim 18, in which said arms are resilient and normally freely assume different positions along the path of travel of said actuating member, so that contact is broken between said actuating component and one of said arms before contact is broken between said actuating component and the other of said arms as said armature moves from its first position.

15. The circuit regulator of claim 18, in which said arms are resilient and are mounted in cantilever fashion on said frame so as to bend about axes displaced from the pivotal axes of said armature when engaged by said actuating component, said arms normally freely assuming, different positions along the path of travel of said actuating member, sothat contact isbroken. between said actuating: member and one of said arms before contact isbroken between said actuating. member and the other of said arms as said armature moves from its first. position,- said armature having. a degree of movement' from the point where said actuating component first engages one of said arms to the first position of said armature, thereby achieving. relative motion between: said actuating component: and: said: arms: while they are engaged so as todefine as Wiping contact en gag'ement.

16. A: circuit regulatinglsystcm comprising a. plurality of regulating circuit components: connected in parallel, a: contact pair in series with each: of said: components and comprising a. fixed contact and a movable contact resiliently urged into engagement therewith, saidcontacts being comparatively flimsy so as to be capable of breaking only small amounts of current, movable means normally disengaged from said: contact pairs and operatively engageable with said contact pairs for sequentially opening them,. andv a short circuit around said circuit components, said short circuit includingfirst and second relatively movable comparatively massive normally engageable but disengageable contacts, and an operative connection between at least the first of said massive contacts and said movable means effective to disengage said massive contacts before any of said con tact pairs are operatively engaged'by said movable means.

17. In the circuit regulatingt system of claim 16, a third comparatively massive contact with respect-to which at least said first massive contact isrelatively movable between engaged and disengaged positions, and an additional regulating circuit component connected between said second and third massive contacts, said second and third massive contacts being'normally displaced from one another along the path of relative movement of saidfirst contact so that said first contact disengages from one of said second and third contacts before the other as said movable means moves toward said contact pairs.

18. A circuit regulator comprising, aframe, an armature pivotally mounted thereon, resilient means operatively connected to said armature so as to urge it to a first position, an electromagnet active on said armature was, when energized, to urge said-armature to a second position against the action of said resilient means, a first circuit-controlling assembly on said frame and compris- Cir ing a plurality of contact pairs each comprising a fixed contact and a movable contact resiliently urged to engagement with said fixed contact, a contact-lifting memberoperatively connected to and positioned by said' armatureout of engagement with said movable contacts when said armature is in its first position and movable by saidarmature, as saidarmature moves to its second' position, into sequential engagement with said movable contacts so as to sequentially move them out of engagement with their respective fixedcontacts, said fixed and mov-' able contacts being comparatively flimsy so as to be capable of breaking only small amounts ofi currents, and a comparatively massive circuit-breaking assembly capable of breaking larger amounts of currents carried by said frame and having an actuating component therefor operatively connected to said armature, saidcomparatively massive circuit-breaking assembly comprising a pair of conductive arms mounted on said frame, extend-- ing adjacent but spaced from one another, and adapted:

to be electrically connected to appropriate circuit elements,- said actuating component comprising a conductive element movable by said armature so asto be simultaneously engaged with both said arms, bridging said arms, when said armature is in its first positiomthereby closing the circuit through said arms, said actuating ele mentbeing disengaged from said arms so as toopen the circuit therethrough as said armature moves toward itsseco'nd' position and before the contact-liftingmember engages any of said movable contacts.

References Cited in the file of this patent UNITED STATES PATENTS 

